Age Pattern Of Ocean Floor

Measurements of the thickness of marine sediments and absolute age determinations of such bottom material have provided additional evidence for seafloor spreading.

Age pattern of ocean floor.

In 1966 vine and matthews and also morley working independently compared these known ages of magnetic reversals with the magnetic striping pattern found on the ocean floor. It is composed of several layers not including the overlying sediment. Age of earth s oceanic crust the age of earth s oceanic crust can be presented to show the pattern of seafloor spreading at the global scale. Examine the color code to understand how the age of rocks changes from the center to the edges of the ocean floor.

Oceanic crust is about 6 km 4 miles thick. When scientists studied the magnetic properties of the. Contours of 20 million years are available as a layer that is currently set to invisible. Oceanic crust the outermost layer of earth s lithosphere that is found under the oceans and formed at spreading centres on oceanic ridges which occur at divergent plate boundaries.

Every once in a while the currents in the liquid core which create the earth s magnetic field reverse themselves. It is called a geomagnetic reversal. The data is from four companion digital models of the age age uncertainty spreading rates and spreading asymmetries of the world s ocean basins. Therefore seafloor dating isn t that useful for studying plate motions beyond the cretaceous.

Rather than height of the ocean floor above a base or reference level the depth of the ocean is of interest. Consider how the age of rocks is related to the shape of the seafloor you saw in step 3. This dataset shows the age of the ocean floor along with the labeled tectonic plates and boundaries. This has happened many times throughout earth s history.

To get the dependence on x one must substitute t x v ax l where l is the distance between the ridge to the continental shelf roughly half the ocean width and a is the ocean basin age. Scientists can determine the age of the seafloor by examining the changing magnetic field of our planet. This graphic shows several ocean floor features on a scale from 0 35 000 feet below sea level. Continental shelf 300 feet continental slope 300 10 000 feet abyssal plain 10 000 feet abyssal hill 3 000 feet up from the abyssal plain seamount 6 000 feet.

Because of this correlation between age and subduction potential very little ocean floor is older than 125 million years and almost none of it is older than 200 million years. For that geologists date and study continental crust. Basalt the once molten rock that makes up most new oceanic crust is a fairly magnetic substance and scientists began using magnetometers to measure the magnetism of the ocean floor in the 1950s what they discovered was that the magnetism of the ocean floor around. The following features are shown at example depths to scale though each feature has a considerable range at which it may occur.